$\dfrac{5}{4} \div \dfrac{3}{5} = {?}$
Answer: Dividing by a fraction is the same as multiplying by the reciprocal of the fraction. The reciprocal of $\dfrac{3}{5}$ is $\dfrac{5}{3}$. Therefore: $ \dfrac{5}{4} \div \dfrac{3}{5} = \dfrac{5}{4} \times \dfrac{5}{3} $ $ \phantom{\dfrac{5}{4} \times \dfrac{5}{3}} = \dfrac{5 \times 5}{4 \times 3} $ $ \phantom{\dfrac{5}{4} \times \dfrac{5}{3}} = \dfrac{25}{12} $